This invention relates to placement of a tarpaulin cover over a payload on a flatbed trailer of the type towed on highways by an appropriately equipped tow truck or tractor.
Many payloads transported on flatbed trailers need to be covered to protect the load from the sun, dust, rain, sleet, snow and the like. Heretofore it has been a common practice to protect vulnerable payloads with a large tarpaulin cover which is relatively heavy. Because of the weight of the tarpaulin cover, the services of several workmen are needed to lift and place the cover on the payload. Typical trailer tarping operations are labor intensive and time-consuming.
Flatbed trailers are typically xe2x80x9ctarpedxe2x80x9d by a substantial number of workmen lifting and tugging a heavy tarpaulin cover over the payload on the flatbed trailer. The tarpaulin cover is heavy and thus requires a considerable number of workmen. The proper number of workman are not always available at the time needed and thus time is wasted waiting for the required number. At some locations workmen are drawn from other work projects, thus causing undesirable interruptions in those projects. Manually moving the tarpaulin cover into a cargo covering position on a flatbed trailer is a difficult job requiring considerable strength and not all workmen are capable of such work or agreeable to engage in such work.
Heretofore others have provided protective covers for various cargo carrying vehicles. U.S. Pat. No. 2,070,586, issued on Feb. 16, 1937 to B. F. Fitch on a Freight container, discloses a freight container having a roof of corrugated metal sheets which may be lifted by a hoist hook.
U.S. Pat. No. 3,994,240, issued Nov. 30, 1976, to R. L. Berg et al. on a Coil Car Cover, describes a light weight removable cover for railroad coil cars which is made of fiberglass reinforced plastic and which includes a lifting cage engageable by the lift hook of a crane.
U.S. Pat. No. 4,050,734 issued Sep. 27, 1977 to D. B. Richard on a Roll-up Truck Cover Assembly, shows a flexible top cover for a dump truck. The flexible cover is wound up on a spring biased take-up roll carried on support arms pivoted by fluid operated cylinders.
U.S. Pat. No. 5,036,775, issued Aug. 6, 1991, to E. D. Snead on a Covered Gondola Car, shows gondola cars covered by rigid covers made of fiberglass which can be removed by a tractor-shovel.
U.S. Pat. No. 5,054,402 issued Oct. 8, 1991, to G. W. Brassell on a Removable Cover for Gondola Cars with Lightweight Composite Panel Construction, discloses removable cover panels having a plastic foam core sandwiched between metal sheets. The cover is removable by connecting a hoist hood to a lift line.
U.S. Pat. No. 5,682,823, issued Nov. 4, 1997, to E. L. Tihansky et al. on a Removable Insulated Cover and Method of Transporting Hot Oversized Steel Ingots, shows a rigid protective housing for a ingot placed on a railroad car by a lifting device.
It is a primary object of this invention to provide a drive-through work station for efficiently installing a tarpaulin cover to a payload on a flatbed highway trailer It is a further object to provide a work station for installing a tarpaulin cover to a flatbed highway trailer which required less manpower than heretofore required. Another object of this invention is the provision of a work station to install a tarpaulin cover to the payload on a flatbed trailer in less time than heretofore required. A further object of the invention is to enhance worker safety, as for instance, by decreasing the chance of workers falling off the trailer during a tarping operation and by providing safe worker movement to and from the flatbed trailer.
The work station of the present invention utilizes a power operated traveling hoist for lifting and moving a tarpaulin cover to its cargo covering position with minimal manpower and in much less time than previously required.
In a preferred embodiment of the invention, one end of the tarpaulin cover is releaseably attached to a hanger on the end of a hoist line or chain of a power operated winch. The power operated winch is mounted on a wheeled carriage supported on an overhead track running lengthwise above the trailer. After the tarpaulin end is raised by the power winch, the carriage is power driven along the support track thereby pulling the tarpaulin cover over the payload on the trailer The towed end of the tarpaulin cover is lowered and disconnected from the hanger. Then the tarpaulin cover is secured to the trailer.
In order to facilitate the operation of the work station a walkway or work platform is preferably provided at one or both lateral sides of the trailer. The work platform may be at the height of the flatbed trailer for trailers transporting loads of low elevation, or it may be at an elevated height for trailers carrying high loads. The work performed affords safe movement of workers to and from the flatbed trailers, and positions for handling and fastening the tarpaulin to the trailer or the cargo.